William Mack

WHAT MAKES HIM HAUTE: Mack is a third generation real estate tycoon best known for co-developing the Time Warner Center. He also heads Apollo Real Estate Advisors, serves as chair of real estate investment trust Mack-Cali Realty, and is chairman of the Guggenheim. As of December 2008, Apollo managed more than $37 billion of investor commitments across its private equity funds and other investment vehicles, making it one of the largest private equity firms in the world.